1. Field of the Invention
The present invention relates to an ink-jet head that ejects ink to a record medium to conduct recordings.
2. Description of Related Art
An ink-jet head having an actuator unit that extends over many pressure chambers is known (see Japanese Patent Unexamined Publication No. 2004-114342). This actuator unit includes piezoelectric sheets that extend over many pressure chambers, and individual electrodes that are formed on an upper face of an uppermost one of the piezoelectric sheets so as to correspond to the respective pressure chambers. A passage unit, which has pressure chambers formed in its upper face and many nozzles formed in its lower face, has this actuator unit bonded to its upper face so that the pressure chambers are covered with the actuator unit. Each individual electrode is electrically connected to a contact of a flexible flat cable such as an FPC (flexible printed circuit), a COF (chip on film), etc.
Driving of the actuator unit causes the piezoelectric sheets to exhibit unimorph deformation by a transversal piezoelectric effect. In order to promote efficiency of deformation of the actuator unit, the flexible cable must be kept out of contact with a region on the piezoelectric sheet corresponding to each pressure chamber. From such a standpoint, in the aforementioned head, a conductive member called a “land” which is thicker than the individual electrode is provided in a region of the piezoelectric sheet corresponding to no pressure chamber such that the land is in contact with the individual electrode. Thus, the individual electrode and the contact of the flexible cable are electrically connected via the land. The piezoelectric sheet has a trapezoidal shape in a plan view, and many dummy electrodes are formed along upper and lower sides of the trapezoidal shape. Each dummy electrode is bonded to a contact of the flexible cable.